Acrylate polymer coated sheet materials and method of production thereof

Abstract

Sheet materials according to the present invention comprise a sheet material substrate, such as for example a film or paper sheet, with a polymer base coating overlying and adhered to a surface of the sheet material substrate. The base coating comprises a radiation cured crosslinked polymer derived from at least one vapor deposited acrylate prepolymer composition having a molecular weight in the range of from about 150 to 600. A metal layer is deposited on and overlies a surface of the base coating, and a polymer top coating overlies and is adhered to a surface of the metal layer. The top coating comprises a radiation cured crosslinked polymer derived from a vapor deposited acrylate prepolymer composition having a molecular weight in the range of from about 150 to 600 and a ratio of its molecular weight to its number of acrylate groups (MW/Ac) in the range of from about 150 to 600. According to one embodiment of the invention, metallized paper sheet materials are produced with superior appearance and performance characteristics which can be tailored to specific end use applications. For example, the metallized paper can be produced with a very shiny, high gloss surface appearance, and/or a high quality metallized layer free of defects or pinholes, and/or an outer surface which is highly receptive to printing.

What is claimed is:  
     
       1. A sheet material comprising: 
       a sheet material substrate;  
       a polymer base coating overlying and adhered to a surface of said sheet material substrate, said base coating comprising a radiation cured crosslinked polymer derived from at least one vapor deposited acrylate prepolymer composition having a molecular weight in the range of from about 150 to 600;  
       a metal layer deposited on and overlying a surface of said base coating; and  
       a polymer top coating overlying and adhered to a surface of said metal layer, said top coating comprising a radiation cured crosslinked polymer derived from a vapor deposited acrylate prepolymer composition having a molecular weight in the range of from about 150 to 600 and a ratio of its molecular weight to its number of acrylate groups (MW/Ac) in the range of from about 150 to 600,  
       wherein said prepolymer composition for said top coating includes a polar acrylate monomer having a dielectric constant of higher than four.  
     
     
       2. A sheet material according to claim  1  wherein said prepolymer composition for said top coating comprises at least 20% by weight of a polyfunctional acrylate monomer. 
     
     
       3. A sheet material according to claim  1  wherein said polar acrylate monomer comprises an acrylate monomer selected from the group consisting of amine acrylates, acid acrylates, ether acrylates and polyol acrylates. 
     
     
       4. A sheet material according to claim  1 , in which the sheet material has fewer than five pinholes per square centimeter of metallized surface. 
     
     
       5. A sheet material according to claim  1 , wherein said sheet material substrate is paper, and the sheet material has a 60 degree surface gloss rating of at least 60. 
     
     
       6. A sheet material according to claim  1  wherein said sheet material substrate comprises a polymer film, and the sheet material has a 60 degree surface gloss rating of at least 60. 
     
     
       7. A sheet material according to claim  1  wherein said polymer base coating comprises a first crosslinked acrylate polymer layer overlying and adhered to said surface of said sheet material substrate and a second crosslinked acrylate polymer layer upon which said metal layer is deposited and adhered. 
     
     
       8. A sheet material according to claim  7  wherein said first and second crosslinked polymer layers of said base coating are of the same acrylate composition, and the layers serve to smooth irregularities present in the surface of said substrate. 
     
     
       9. A sheet material according to claim  7  wherein said first and second crosslinked polymer layers of said base coating are of differing acrylate compositions, and said second layer is derived from a vapor deposited acrylate prepolymer composition having a ratio of its molecular weight to its number of acrylate groups (MW/Ac) in the range of from about 150 to 600. 
     
     
       10. A sheet material according to claim  7 , wherein said polymer top coating comprises a first crosslinked acrylate polymer layer overlying and adhered to said surface of said metal layer and a second crosslinked acrylate polymer layer forming an exterior surface of the sheet material. 
     
     
       11. A sheet material according to claim  1  wherein said polymer top coating comprises a first crosslinked acrylate polymer layer overlying and adhered to said surface of said metal layer and a second crosslinked acrylate polymer layer forming an exterior surface of the sheet material. 
     
     
       12. A sheet material according to claim  11  wherein said first crosslinked polymer layer is derived from a polyfunctional acrylate monomer and a polar acrylate monomer having a dielectric constant of  4  or higher. 
     
     
       13. A sheet material according to claim  11  wherein said first and second crosslinked polymer layers are of the same or differing acrylate compositions, and said first layer is derived from a polyfunctional acrylate monomer having a ratio of its molecular weight to its number of acrylate groups (MW/Ac) in the range of from about 150 to 600. 
     
     
       14. A sheet material according to claim  13 , additionally including a layer of printing adhered to said exterior surface of the sheet material. 
     
     
       15. A sheet material according to claim  11 , wherein said second layer which forms the exterior surface of the sheet material has a thickness of 3 microns or less. 
     
     
       16. A sheet material according to claim  11 , wherein said substrate is paper, and additionally including a layer of printing adhered to said exterior surface of the sheet material. 
     
     
       17. A sheet material according to claim  1  further comprising a final coating having at least one crosslinked acrylate polymer layer and at least one metal layer, wherein each crosslinked acrylate polymer layer overlies and adheres to the previously deposited metal layer, wherein one of the crosslinked acrylate polymer layers forms an exterior surface of the sheet material and has a thickness of less than 3 microns. 
     
     
       18. A sheet material according to claim  1 , wherein said polymer base coating comprises at least one first crosslinked acrylate polymer layer overlying and adhered to said surface of said sheet material substrate and a final crosslinked acrylate polymer layer upon which said metal layer is deposited and adhered. 
     
     
       19. A sheet material according to claim  18 , wherein said crosslinked polymer layers of said base coating are of the same acrylate composition, and the layers serve to smooth irregularities present in the surface of said substrate. 
     
     
       20. A sheet material according to claim  1 , wherein said polymer base coating comprises a first crosslinked acrylate polymer layer overlying and adhered to said surface of said substrate and a second crosslinked acrylate polymer layer overlying and adhered to said first polymer layer, wherein the first polymer layer has more than one layer of the same composition. 
     
     
       21. A sheet material according to claim  1 , wherein at least one of the polymer base coating and the polymer top coating comprises at least one layer of a first crosslinked acrylate polymer and at least one layer of a second crosslinked acrylate polymer, wherein each second crosslinked acrylate polymer layer overlies and adheres to the previously deposited first crosslinked acrylate polymer layer. 
     
     
       22. A metallized paper sheet comprising: 
       a paper substrate;  
       a polymer base coating overlying and adhered to a surface of said paper substrate, said base coating comprising at least one layer of radiation cured crosslinked polymer derived from at least one vapor deposited acrylate prepolymer composition having a molecular weight in the range of from about 150 to 600;  
       a metal layer deposited on and overlying a surface of said base coating;  
       a polymer top coating overlying and adhered to a surface of said metal layer, said top coating comprising at least one layer of a radiation cured crosslinked polymer derived from a polyfunctional acrylate monomer having a molecular weight in the range of from about 150 to 600 and a polar acrylate monomer having a molecular weight in the range of from about 150 to 600; and  
       said metallized paper sheet having a 60 degree surface gloss rating of at least 60,  
       wherein said polar acrylate monomer has a dielectric constant of higher than four.  
     
     
       23. A metallized paper sheet as recited in claim  22  wherein said at least one layer of crosslinked polymer derived from a polyfunctional acrylate monomer and a polar acrylate monomer is derived from at least 20% by weight of said polyfunctional acrylate monomer, and wherein said polar acrylate monomer comprises an acrylate monomer selected from the group consisting of amine acrylates, acid acrylates, ether acrylates and polyol acrylates. 
     
     
       24. A metallized paper sheet as recited in claim  22  wherein said polymer top coating comprises a first crosslinked acrylate polymer layer overlying and adhered to said surface of said metal layer and a second crosslinked acrylate polymer layer forming an exterior surface of the metallized sheet material, and wherein said first crosslinked acrylate polymer layer is derived from a polyfunctional acrylate monomer and a polar acrylate monomer selected from the group consisting of amine acrylates, acid acrylates, ether acrylates and polyol acrylates, said monomers having a ratio of molecular weight to number of acrylate groups (MW/Ac) within the range of from 150 to 600. 
     
     
       25. A metallized paper sheet comprising: 
       a paper substrate;  
       a radiation cured crosslinked polymer base coating adhered to a surface of said substrate, said polymer base coating comprising at least one radiation cured crosslinked acrylate polymer layer,  
       a metal layer deposited on a surface of said radiation cured crosslinked polymer base coating; and  
       a top coating of radiation cured crosslinked polymer overlying said metal layer, said top coating comprising a first radiation cured crosslinked acrylate polymer layer adhered to a surface of said metal layer and a second radiation cured crosslinked acrylate polymer layer adhered to the first polymer layer, and  
       wherein at least said first acrylate polymer layer is derived from a vapor deposited acrylate prepolymer composition having a ratio of molecular weight to number of acrylate groups (MW/Ac) in the range of about 150 to 600 and comprising a polyfunctional acrylate monomer and a polar acrylate monomer selected from the group consisting of amine acrylates, acid acrylates, ether acrylates and polyol acrylates,  
       wherein said polar acrylate monomer has a dielectric constant of higher than four.  
     
     
       26. A sheet material according to claim  25 , wherein said second acrylate polymer layer of said top coating is derived from a vapor deposited acrylate prepolymer composition having a ratio of molecular weight to number of acrylate groups (MW/Ac) in the range of about 150 to 600 and comprising a polyfunctional acrylate monomer and a polar acrylate monomer selected from the group consisting of amine acrylates, acid acrylates, ether acrylates and polyol acrylates, and said sheet material additionally includes a layer of printing adhered to said second acrylate polymer layer of said top coating. 
     
     
       27. A sheet material comprising: 
       a metallic sheet material substrate; and  
       a polymer coating overlying and adhered to a surface of said metallic sheet material substrate, said coating comprising a radiation cured crosslinked polymer derived from a vapor deposited acrylate prepolymer composition having a molecular weight in the range of from about 150 to 600 and a ratio of its molecular weight to its number of acrylate groups (MW/Ac) of in the range of from about 150 to 600, said prepolymer composition comprising at least 20% by weight of a polyfunctional acrylate monomer and a polar acrylate monomer having a dielectric constant of higher than four.  
     
     
       28. A sheet material according to claim  27  wherein said polar acrylate monomer comprises an acrylate monomer selected from the group consisting of amine acrylates, acid acrylates, ether acrylates and polyol acrylates. 
     
     
       29. A sheet material according to claim  27 , wherein said polymer is derived from at least 50 percent by weight of said polyfunctional acrylate monomer and at least 10 percent of said polar acrylate monomer. 
     
     
       30. A sheet material according to claim  27 , wherein said radiation cured crosslinked polymer has a thickness of 3 microns or less. 
     
     
       31. A sheet material according to claim  27 , wherein said polymer coating comprises a first crosslinked acrylate polymer layer overlying and adhered to said surface of said substrate and a second crosslinked acrylate polymer layer overlying and adhered to said first polymer layer. 
     
     
       32. A sheet material according to claim  31  wherein said first and second crosslinked polymer layers of said base coating are of differing acrylate compositions, and said first layer is derived from a vapor deposited acrylate prepolymer composition having a ratio of its molecular weight to its number of acrylate groups (MW/Ac) in the range of from about 150 to 600. 
     
     
       33. A sheet material according to claim  27  wherein said metallic sheet material substrate comprises a metallized paper substrate. 
     
     
       34. A sheet material according to claim  33  wherein said metallized paper substrate comprises a porous paper layer, a polymer base coating overlying and adhered to a surface of said paper layer, said base coating comprising at least one layer of radiation cured crosslinked polymer derived from a vapor deposited acrylate prepolymer composition, and a vapor deposited metal layer adhered to and overlying a surface of said base coating and forming a substantially pinhole-free metal coating. 
     
     
       35. A sheet material according to claim  27  wherein said metallic sheet material substrate comprises a metallized polymer film substrate. 
     
     
       36. A sheet material comprising: 
       a metallic sheet material substrate;  
       a polymer coating overlying and adhered to a surface of said sheet material substrate, said coating comprising a first radiation cured crosslinked acrylate polymer layer overlying and adhered to said surface of said sheet material substrate and a second radiation cured crosslinked acrylate polymer layer overlying and adhered to said first crosslinked acrylate polymer layer, said first acrylate polymer layer being derived from a vapor deposited acrylate prepolymer composition having a ratio of its molecular weight to its number of acrylate groups (MW/Ac) in the range of from about 150 to 600, said prepolymer composition comprising a polyfunctional acrylate monomer and a polar acrylate monomer having a dielectric constant of higher than four.  
     
     
       37. A sheet material according to claim  36  wherein said first acrylate polymer layer is derived from at least 20% by weight of said polyfunctional acrylate monomer, and wherein said polar acrylate monomer comprises an acrylate monomer selected from the group consisting of amine acrylates, acid acrylates, ether acrylates and polyol acrylates. 
     
     
       38. A sheet material according to claim  36  wherein said second acrylate polymer layer has a thickness of 3 microns or less and is derived from vapor deposited 100 percent solids monomers and has no residual solvent present. 
     
     
       39. A sheet material according to claim  36  wherein said metallic sheet material substrate comprises metallized paper, and the sheet material has a 60 degree surface gloss rating of at least 60. 
     
     
       40. A sheet material comprising: 
       a sheet material substrate;  
       a polymer coating overlying and adhered to a surface of said sheet material substrate, said coating comprising a radiation cured crosslinked polymer derived from at least one vapor deposited acrylate prepolymer composition having a molecular weight in the range of from about 150 to 600, said prepolymer composition comprising a polyfunctional acrylate monomer and a polar acrylate monomer selected from the group consisting of amine acrylates, acid acrylates, ether acrylates and polyol acrylates,  
       wherein said polar acrylate monomer has a dielectric constant of higher than four.  
     
     
       41. A sheet material according to claim  40 , wherein said polyfunctional acrylate monomer has a ratio of its molecular weight to its number of acrylate groups (MW/Ac) of at least 150 and less than 600. 
     
     
       42. A sheet material according to claim  40 , additionally including a metal layer deposited on and overlying a surface of said polymer coating. 
     
     
       43. A sheet material according to claim  40 , wherein said polymer coating comprises a first crosslinked acrylate polymer layer overlying and adhered to said surface of said substrate and a second crosslinked acrylate polymer layer overlying and adhered to said first polymer layer. 
     
     
       44. A sheet material according to claim  43  wherein said first crosslinked polymer layer comprises said polyfunctional acrylate monomer having a ratio of its molecular weight to its number of acrylate groups (MW/Ac) in the range of from about 150 to 600. 
     
     
       45. A sheet material according to claim  43  wherein said first and second crosslinked polymer layers are of the same or differing acrylate compositions, and said second layer comprises said polyfunctional acrylate monomer having a ratio of its molecular weight to its number of acrylate groups (MW/Ac) in the range of from about 150 to 600. 
     
     
       46. A sheet material according to claim  43  additionally including a metal layer deposited on and overlying a surface of said second layer and said sheet material has a 60 degree surface gloss rating of at least 60. 
     
     
       47. A sheet material comprising: 
       a sheet material substrate;  
       a polymer coating overlying and adhered to a surface of said sheet material substrate, said coating comprising a first radiation cured crosslinked acrylate polymer layer overlying and adhered to said surface of said sheet material substrate and a second radiation cured crosslinked acrylate polymer layer overlying and adhered to said first crosslinked acrylate polymer layer, said second acrylate polymer layer being derived from a vapor deposited polyfunctional acrylate monomer having molecular weight in the range of from about 150 to 600 and a ratio of its molecular weight to its number of acrylate groups (MW/Ac) in the range of from about 150 to 600 and a vapor deposited polar acrylate monomer having a dielectric constant of higher than four.  
     
     
       48. A sheet material according to claim  47  wherein said second acrylate polymer layer is derived from at least 20% by weight of said polyfunctional acrylate monomer, and wherein said polar acrylate monomer comprises an acrylate monomer selected from the group consisting of amine acrylates, acid acrylates, ether acrylates and polyol acrylates. 
     
     
       49. A sheet material according to claim  47  wherein said second acrylate polymer layer has an acidity equivalent to that provided by at least 10% by weight beta carboxy ethyl acrylate. 
     
     
       50. A sheet material according to claim  47  wherein said second acrylate polymer layer has a thickness of 3 microns or less and is derived from vapor deposited 100 percent solids monomers and has no residual solvent present. 
     
     
       51. A sheet material according to claim  47  wherein said sheet material substrate is paper, and additionally including a metal layer deposited on and overlying a surface of said second layer, and wherein said sheet material has a 60 degree surface gloss rating of at least 60.